摘要
本文针对智能反射面辅助的太赫兹卫星通信系统,提出一种基于用户非完美信道状态信息的鲁棒安全波束成形算法,以提升系统的物理层安全性能.首先,在智能反射面辅助的太赫兹卫星系统采用多播传输技术向多个合法用户发送信号,并且在其覆盖区域内存在多个窃听者的场景下,建立以卫星发射功率最小化为目标函数,合法用户的可达速率和可达安全速率满足要求为约束的联合优化问题.其次,考虑到非完美信道状态信息导致可达速率和可达安全速率均为非凸的概率约束,提出采用二阶泰勒展开和S程序方法对其进行转化,并进一步通过半正定规划完成智能反射面的相移矩阵和卫星发射功率的联合优化设计.最后,计算机仿真验证了所提算法的有效性和优越性.
In this paper,a robust secure beamforming scheme based on imperfect channel state information(CSI)is proposed for the intelligent reflecting surface(IRS)-aided terahertz satellite communication systems,in order to improve the physical layer security performance of the system.First,we consider a scenario where an IRS-aided terahertz satellite sys⁃tem adopts multicast technique to serve multiple legitimate users in the presence of multiple eavesdroppers in the coverage area,based on which a joint optimization problem is formulated in order to minimize the satellite transmit power under the constraints constructed by the achievable rate(AR)and the achievable secrecy rate(ASR)requirements of each legitimate users.Secondly,considering that AR and ASR are non-convex probabilistic constraints caused by imperfect CSI,an ap⁃proach associated with the second-order Taylor expansion and S-procedure is proposed to transform the non-convex con⁃straints.Further,the joint optimization scheme of the phase shift of IRS and the transmit power of satellite can be solved by semidefinite programming.Finally,the effectiveness and superiority of the proposed scheme are verified by simulation results.
作者
林敏
李菲
王子宁
赵柏
韩略
LIN Min;LI Fei;WANG Zi-ning;ZHAO Bai;HAN Lue(College of Telecommunications and Information Engineering,Nanjing University of Posts and Telecommunications,Nanjing,Jiangsu 210003,China)
出处
《电子学报》
EI
CAS
CSCD
北大核心
2023年第10期2715-2723,共9页
Acta Electronica Sinica
基金
重点国际合作项目(No.61720106003)
南京邮电大学引进人才科研启动项目(No.NY220111)
江苏省研究生科研与实践创新计划项目(No.KYCX22_0959)。
关键词
卫星通信
智能反射面
物理层安全
鲁棒波束成形
太赫兹频段
satellite communications
intelligent reflecting surface
physical layer security
robust beamforming
terahertz band
